The skin is a vital organ composed of several layers (dermis, proliferative layers and stratum corneum), which covers the entire surface of the body and ensures protective, sensitive, immune, metabolic or thermoregulatory functions. The skin, like the other organs, is subject to aging.
For example, the appearance of the skin is modified by various types of internal (disease and hormonal changes such as pregnancy) or external aggressions (environmental factors, such as pollution, sunlight, pathogens, etc.). Then wrinkles and fine lines, hyperpigmentation or hypopigmentation blemishes, dryness or even dehydration of the skin, thinning of the epidermis, elastosis, imperfections, age spots, etc., may appear. All of these changes affect not only the skin, but also the keratinous appendages such as the nails and hair.
It is known that free radicals, chemically unstable and very reactive species generated by the intracellular metabolism or external aggressions, play a key role in the aging process and more particularly in the formation of oxidized, damaged proteins (Harman et al. “Aging: a theory based on free radical and radiation chemistry” J. Gerontol., 11, 298-300). These external aggressions can include: ultraviolet radiation, toxins, atmospheric pollutants, alimentary oxidants. Ultraviolet radiations skin exposure induces extensive generation of reactive oxygen species (ROS). These can react with DNA, proteins, fatty acids and saccharides causing oxidative damage.
In the skin, premature aging is observed, occurring in the areas exposed to ultraviolet radiation, characterized by phenomena of alteration to the macromolecules (lipidic peroxidation, carbonylation of proteins), affecting in particular elastin, collagen or fibronectin.
One of the important consequences of the accumulation of oxidative damage is a reduction in the capacity of the cell to produce ATP (Porteous et al., Eur J Biochem 1998, 257(1):192-201). Thus, the phenomenon of cellular aging is in relation to the oxidative damage which the cell undergoes, but also to the process of energy production necessary for the cell to survive.
The human sirtuin family comprises 7 proteins, very conserved throughout evolution, named SIRT1 to SIRT7. “SIRT2 protein” is predominantly located in the cytoplasm and plays roles in oxidative stress response, inflammation, mitotic progression, microtubule dynamics, cell migration, longevity. In cytoplasm, SIRT2 co-localizes with and deacetylates microtubules. During mitosis, it is translocated to the nucleus where it deacetylates histone and regulates chromosomal condensation (Serrano L. et al., “The tumor suppressor SirT2 regulates cell cycle progression and genome stability by modulating the mitotic deposition of H4K20 methylation”, Genes & Dev. 2013. 27: 639-653). Thereby, SIRT2 plays mitotic checkpoint role: it regulates the mitotic progression and the mitotic exit (Bosch-Presegué L. and Vaquero A., “Sirtuins in stress response: guardians of the genome”, Oncogene (2014) 33, 3764-3775). Moreover, the stability of spindle assembly checkpoint protein BubR1 is under control of SIRT2 and a decline in BubR1 over time has been linked to mammalian aging (North B. J. et al., “SIRT2 induces the checkpoint kinase BubR1 to increase lifespan”, The EMBO Journal, 2014, 33, Issue 13, 1438-1453). SIRT2 can therefore be associated with increased cell longevity through BubR1 pathway preservation.
Deacetylation of Lys668 of BubR1 by SIRT2 inhibits the ubiquitination of BubR1 and its designation to the proteasome. Germline mutation that reduce BubR1 abundance cause aneuploidy.
From the state of the art, numerous cosmetics are known which in some way contain plant-based raw materials in the form of oils or extracts. In most cases, the known advantageous effects of individual plants are used to achieve a corresponding overall effect.
The aim of the invention was to develop a novel plant extract exhibiting activation of the SIRT2 expression. Patent EP1868632 disclosed synthetic peptides able to activate endogenous synthesis of sirtuin (SIRT1) protein and have been identified by inventors to be able to activate SIRT 2. Based on this knowledge, the inventors searched for botanicals comprising sequence homology to those identified activating SIRT2 peptides. Sequence similarity searches to identify homologous sequences were performed using comprehensive protein sequence data bases like BLAST following standard procedures (William Pearson, “An Introduction to Sequence Similarity (“Homology”) searching”, Curr Protoc Bioinformatics. June 2013). This search allowed the inventors to select Prunus persica as a good candidate.
The peach flower extract according to the invention has shown an increased expression of sirtuin SIRT2 proteins in the skin.
The species name Prunus persica refers to its widespread cultivation in Persia, whence it was transplanted to Europe. It belongs to the genus Prunus which includes the cherry and plum, in the family Rosaceae. Genetic studies suggest peaches originated in China, where they have been cultivated since the early days of Chinese culture circa 2000 BC.
Prunus persica has long been used in Chinese medicine for treating skin disorder. In Korea, flowers have always been a favorite source of inspiration for women and men of letters. In addition to this quality of muse, flowers have been used in the life of every day, for food decoration or infusions.
The peach blossom is the symbol of Korea Feminine Beauty. The infusion with peach blossoms was once very popular among women of high social rank who knew its beneficial properties for the skin tone. Peach blossom, popularly consumed as tea, is believed to promote healthy, young-looking skin. The literature reporting pharmacological studies related to peach blossom is very limited.
Peach flower is known to be very rich in polyphenolic compounds, such as phenolic acids, and flavonoids. These molecules can act as scavengers of superoxide anions, singlet oxygen, hydroxyl radicals, and lipid peroxyl radicals. Many flavonoids such as quercetin, luteolin and catechins are better antioxidants than the nutrients vitamin C and beta-carotene (Svobodova et al., “Natural phenolics in the prevention of UV-induced skin damage. A Review” Biomed. Papers 147(2), 137-145 (2003)). The controlled hydrolysis enables these compounds to be released. The peach leaves are used as an anthelmintic, and sedative in traditional medicine (Nadkarni, 1976). Cevallos-Casals et al. reported that peach fruits rich in phenolic and anthocyanin have good antioxidant and antimicrobial activities (Cevallos-Casals et al., “Selecting new peach and plum genotypes rich in phenolic compounds and enhanced functional properties”, Food Chemistry 96 (2006) 273-280). The pink-colored peach blossom flowers, popularly consumed as tea, are purgative and are believed to promote healthy, young-looking skin. The peach blossom is the symbol of Korea Feminine Beauty. The infusion with peach blossoms was once very popular among women of high social rank who knew its beneficial properties for the skin tone.
Some flavonoids have been identified in peach flower such as the kaempferol glycoside derivatives multiflora B, trifolin, afzelin, and astragalin. In addition, a skin protection effect was demonstrated for multiflora B (Young ha Kim et al., “The extract of the flowers of Prunus persica, a new cosmetic ingredient, protects against solar ultraviolet-induced skin damage in vivo”, j. Cosmet. Sci., 53, 27-34 (January/February 2002)).
Peach flowers which are pink in color have been used to obtain the extract. Flowers are rich in polyphenolic compounds and also in flavonoids in particular pink flower are also rich in particular flavonoids, the anthocyanins that give the pink color to the flower in comparison to white flower.
Anthocyanins have been demonstrated to have a broad spectrum of biological functions and may act as good antioxidant like other members of flavonoids family.
Antioxidants play an important role as health protecting factor. Primary sources of naturally occurring antioxidants are whole grains, fruits, flower and vegetables. Plant antioxidants are vitamin C, vitamin E, carotenes, phenolic acid, flavonoids. They have been recognized as having the potential to reduce disease risk, anti-aging effect. The antioxidant effect of pink peach blossom extract has been investigated according to the method of 2,2-Diphenyl-1-picrylhydrazyl (DPPH).
The use of peach extract in a cosmetic composition is known in prior art. Most extract are total extracts or water-alcohol extracts. For example, the Japanese patent application, JP-A-2001302439 has disclosed a cosmetic having inhibitory action on elastases and collagenases for prevention of skin aging by including an extract from white Prunus Persia Batsh obtained by high temperature extracting process. Korean patent, KR-526637 has disclosed an anti-ultraviolet and cosmetic composition for skin aging protection including ferulic acid and peach blossom extract in which the stability of skin including the extract from peach Blossom of 0.1-20.0 weight % and ferulic acid of 0.1-20.0 weight % in the active ingredient is improved. Japanese patent application, JP-A-2016053008 has disclosed a manufacturing method of the peach extract which has the active oxygen eliminating ability carrying out partition extraction of the obtained extract with hexane/water further, and contains sphingoglycolipid (ceramide component). Korean patent, KR-1429117 has disclosed a composition for skin whitening containing peach blossom extract obtained by a step of removing the flower (fuse) from the peach blossom and using only the calyx, drying the sample, pulverizing the sample, subjecting to the homogenizer. With the step of extracting in the solvent selected in the group consisting of water, lower alcohol of the C3-6 and lower organic acid of the C3-6. The obtained extract is freeze-dried after it filtering with filter paper. Unlike the prior art, the present application provides an effective process for extraction of peach flower extract with high polyphenol content and free of ceramide.
In spite of the various anti-aging cosmetic products on the market for the treatment of skin, there remains a need for effective topically applied cosmetic compositions that provide anti-aging or rejuvenating benefits to the skin, hair and/or nails using natural ingredients as active agent. Unnatural, chemically-synthesized products may be perceived as being environmentally or personally unsafe. In contrast, natural products are perceived as pure, mild, and superior to chemically synthesized products. Numerous natural based products extracted from plants or herbs are known to contain antioxidant/free-radical scavenging agents that can neutralize the effects of free-radical damage. Additionally, they can contain agents that stimulate the synthesis and restoration of damaged connective tissue structures in the dermis and barrier function in the epidermis.
There remains a need for cosmetic compositions which address the signs of aging, in particular the appearance of wrinkles, lines, and sagging. It is therefore an object of the present invention to provide new compositions and methods for treating, ameliorating, and/or preventing signs of aged or aging skin. It is a further object of the invention to improve the overall appearance of aging or aged skin.
The foregoing introduction is presented solely to provide a better understanding of the nature of the problems confronting the art and should not be construed in any way as an admission as to prior art nor should the citation of any reference herein be construed as an admission that such reference constitutes “prior art” to the instant application.